/* $Id: rpc_scan.c,v 1.4 2006/05/30 00:00:19 dm Exp $ */
/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user or with the express written consent of
 * Sun Microsystems, Inc.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * rpc_scan.c, Scanner for the RPC protocol compiler 
 * Copyright (C) 1987, Sun Microsystems, Inc. 
 */
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include "rpc_scan.h"
#include "rpc_parse.h"
#include "rpc_util.h"

static void unget_token (token * tokp);
static void findstrconst (char **, char **);
static void findchrconst (char **, char **);
static void findconst (char **, char **);
static void findkind (char **, token *);
static int cppline (char *);
static int directive (char *);
static void printdirective (char *);
static void docppline (char *, int *, char **);

#define startcomment(where) (where[0] == '/' && where[1] == '*')
#define endcomment(where) (where[-1] == '*' && where[0] == '/')

static int pushed = 0;		/* is a token pushed */
static token lasttok;		/* last token, if pushed */

/*
 * scan expecting 1 given token 
 */
void
scan (tok_kind expect, token * tokp)
{
  get_token (tokp);
  if (tokp->kind != expect) {
    expected1 (expect);
  }
}

/*
 * scan expecting any of the 2 given tokens 
 */
void
scan2 (tok_kind expect1, tok_kind expect2, token * tokp)
{
  get_token (tokp);
  if (tokp->kind != expect1 && tokp->kind != expect2) {
    expected2 (expect1, expect2);
  }
}

/*
 * scan expecting any of the 3 given token 
 */
void
scan3 (tok_kind expect1, tok_kind expect2, tok_kind expect3, token * tokp)
{
  get_token (tokp);
  if (tokp->kind != expect1 && tokp->kind != expect2
      && tokp->kind != expect3) {
    expected3 (expect1, expect2, expect3);
  }
}

/*
 * scan expecting a constant, possibly symbolic 
 */
void
scan_num (token * tokp)
{
  get_token (tokp);
  switch (tokp->kind) {
  case TOK_IDENT:
    break;
  default:
    error ("constant or identifier expected");
  }
}

/*
 * Peek at the next token 
 */
void
peek (token * tokp)
{
  get_token (tokp);
  unget_token (tokp);
}

/*
 * Peek at the next token and scan it if it matches what you expect 
 */
int
peekscan (tok_kind expect, token * tokp)
{
  peek (tokp);
  if (tokp->kind == expect) {
    get_token (tokp);
    return (1);
  }
  return (0);
}

/*
 * Get the next token, printing out any directive that are encountered. 
 */
void
get_token (token * tokp)
{
  int commenting;

  if (pushed) {
    pushed = 0;
    *tokp = lasttok;
    return;
  }
  commenting = 0;
  for (;;) {
    if (*where == 0) {
      for (;;) {
	if (!fgets (curline, MAXLINESIZE, fin)) {
	  tokp->kind = TOK_EOF;
	  *where = 0;
	  return;
	}
	linenum++;
	if (commenting) {
	  break;
	}
	else if (cppline (curline)) {
	  docppline (curline, &linenum,
		     &infilename);
	}
	else if (directive (curline)) {
	  printdirective (curline);
	}
	else {
	  break;
	}
      }
      where = curline;
    }
    else if (isspace (*where)) {
      while (isspace (*where)) {
	where++;		/* eat */
      }
    }
    else if (commenting) {
      for (where++; *where; where++) {
	if (endcomment (where)) {
	  where++;
	  commenting--;
	  break;
	}
      }
    }
    else if (startcomment (where)) {
      where += 2;
      commenting++;
    }
    else {
      break;
    }
  }

  /*
   * 'where' is not whitespace, comment or directive Must be a token! 
   */
  switch (*where) {
  case ':':
    tokp->kind = TOK_COLON;
    where++;
    break;
  case ';':
    tokp->kind = TOK_SEMICOLON;
    where++;
    break;
  case ',':
    tokp->kind = TOK_COMMA;
    where++;
    break;
  case '=':
    tokp->kind = TOK_EQUAL;
    where++;
    break;
  case '*':
    tokp->kind = TOK_STAR;
    where++;
    break;
  case '[':
    tokp->kind = TOK_LBRACKET;
    where++;
    break;
  case ']':
    tokp->kind = TOK_RBRACKET;
    where++;
    break;
  case '{':
    tokp->kind = TOK_LBRACE;
    where++;
    break;
  case '}':
    tokp->kind = TOK_RBRACE;
    where++;
    break;
  case '(':
    tokp->kind = TOK_LPAREN;
    where++;
    break;
  case ')':
    tokp->kind = TOK_RPAREN;
    where++;
    break;
  case '<':
    tokp->kind = TOK_LANGLE;
    where++;
    break;
  case '>':
    tokp->kind = TOK_RANGLE;
    where++;
    break;

  case '"':
    tokp->kind = TOK_STRCONST;
    findstrconst (&where, &tokp->str);
    break;
  case '\'':
    tokp->kind = TOK_CHARCONST;
    findchrconst (&where, &tokp->str);
    break;

  case '-':
  case '0':
  case '1':
  case '2':
  case '3':
  case '4':
  case '5':
  case '6':
  case '7':
  case '8':
  case '9':
    tokp->kind = TOK_IDENT;
    findconst (&where, &tokp->str);
    break;

  default:
    if (!(isalpha (*where) || *where == '_')) {
      char buf[100];
      char *p;

      s_print (buf, "illegal character in file: ");
      p = buf + strlen (buf);
      if (isprint (*where)) {
	s_print (p, "%c", *where);
      }
      else {
	s_print (p, "%d", *where);
      }
      error (buf);
    }
    findkind (&where, tokp);
    break;
  }
}

static void
unget_token (token * tokp)
{
  lasttok = *tokp;
  pushed = 1;
}

static void
findstrconst (char **str, char **val)
{
  char *p;
  int size;

  p = *str;
  do {
    p++;
  } while (*p && *p != '"');
  if (*p == 0) {
    error ("unterminated string constant");
  }
  p++;
  size = p - *str;
  *val = alloc (size + 1);
  (void) strncpy (*val, *str, size);
  (*val)[size] = 0;
  *str = p;
}

static void
findchrconst (char **str, char **val)
{
  char *p;
  int size;

  p = *str;
  do {
    p++;
  } while (*p && *p != '\'');
  if (*p == 0) {
    error ("unterminated string constant");
  }
  p++;
  size = p - *str;
  if (size != 3) {
    error ("empty char string");
  }
  *val = alloc (size + 1);
  (void) strncpy (*val, *str, size);
  (*val)[size] = 0;
  *str = p;
}

static void
findconst (char **str, char **val)
{
  char *p;
  int size;

  p = *str;
  if (*p == '0' && *(p + 1) == 'x') {
    p++;
    do {
      p++;
    } while (isxdigit (*p));
  }
  else {
    do {
      p++;
    } while (isdigit (*p));
  }
  size = p - *str;
  *val = alloc (size + 1);
  (void) strncpy (*val, *str, size);
  (*val)[size] = 0;
  *str = p;
}

static token symbols[] =
{
  {TOK_CONST, "const"},
  {TOK_UNION, "union"},
  {TOK_SWITCH, "switch"},
  {TOK_CASE, "case"},
  {TOK_DEFAULT, "default"},
  {TOK_STRUCT, "struct"},
  {TOK_TYPEDEF, "typedef"},
  {TOK_ENUM, "enum"},
  {TOK_OPAQUE, "opaque"},
  {TOK_BOOL, "bool"},
  {TOK_VOID, "void"},
  {TOK_CHAR, "char"},
  {TOK_INT, "int"},
  {TOK_HYPER, "hyper"},
  {TOK_UNSIGNED, "unsigned"},
  {TOK_SHORT, "short"},
  {TOK_LONG, "long"},
  {TOK_FLOAT, "float"},
  {TOK_DOUBLE, "double"},
  {TOK_STRING, "string"},
  {TOK_PROGRAM, "program"},
  {TOK_VERSION, "version"},
  {TOK_EOF, "??????"},
};

static void
findkind (char **mark, token * tokp)
{
  int len;
  token *s;
  char *str;

  str = *mark;
  for (s = symbols; s->kind != TOK_EOF; s++) {
    len = strlen (s->str);
    if (strncmp (str, s->str, len) == 0) {
      if (!isalnum (str[len]) && str[len] != '_') {
	tokp->kind = s->kind;
	tokp->str = s->str;
	*mark = str + len;
	return;
      }
    }
  }
  tokp->kind = TOK_IDENT;
  for (len = 0; isalnum (str[len]) || str[len] == '_'; len++);
  tokp->str = alloc (len + 1);
  (void) strncpy (tokp->str, str, len);
  tokp->str[len] = 0;
  *mark = str + len;
}

static int
cppline (char *line)
{
  return (line == curline && *line == '#');
}

static int
directive (char *line)
{
  return (line == curline && *line == '%');
}

static void
printdirective (char *line)
{
  f_print (fout, "%s", line + 1);
}

static void
docppline (char *line, int *lineno, char **fname)
{
  char *file;
  int num;
  char *p;

  line++;
  while (isspace (*line)) {
    line++;
  }
  if (!strncmp (line, "pragma ", 7))
    return;
  num = atoi (line);
  while (isdigit (*line)) {
    line++;
  }
  while (isspace (*line)) {
    line++;
  }
  if (*line != '"') {
    error ("preprocessor error");
  }
  line++;
  p = file = alloc (strlen (line) + 1);
  while (*line && *line != '"') {
    *p++ = *line++;
  }
  if (*line == 0) {
    error ("preprocessor error");
  }
  *p = 0;
  if (*file == 0) {
    *fname = NULL;
  }
  else {
    *fname = file;
  }
  *lineno = num - 1;
}
